一、概论许多国家由于寿命延长和出生率降低,随着儿童比例的减少,老年人口迅速增长,其中女性明显多于男性。美国1900年,65岁以上的人口为4％,目前已占11％。澳大利亚1980年为总人口9.6％,预计到本世纪末将为11.7％。瑞典1950年65岁以上人口已占10％,到本世纪末将达16％。即使较为年轻的加拿大,65岁以上人口预计2000年将为1964年的一倍以上。但最使人吃惊的是澳大利亚75岁以上人口自1901年迄今已增加了6倍,预测到1991年还要再增加2倍半。民主德国根据法定退休年龄,男性65岁、女性60岁计算,七十年代退休人员达到高峰,占全人口的18.9％。毫无疑问,这些增加的老年 I. Introduction In many countries, due to prolonged life expectancy and reduced birth rates, the number of older people has increased rapidly with the decrease in the proportion of children, of which women are significantly more than men. In the United States in 1900, the population over the age of 65 was 4%, which currently accounts for 11%. Australia had a total population of 9.6% in 1980 and is expected to be 11.7% by the end of the century. In Sweden, the population over 65 years old has occupied 10% in 1950 and will reach 16% by the end of the century. Even in younger Canada, the population aged over 65 is expected to more than double in 1964 from 2000. But what is most surprising is that Australia’s population over the age of 75 has increased sixfold since 1901 and is expected to increase by a further two and a half times by 1991. According to the statutory retirement age, men in Germany are 65 years old and 60 years old. In the 1970s, retirees peaked, accounting for 18.9% of the total population. There is no doubt that these increased old age